<?php

/**
 * CLinkPager class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CLinkPager displays a list of hyperlinks that lead to different pages of target.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.web.widgets.pagers
 * @since 1.0
 */
class MyPage extends CBasePager
{
    const CSS_FIRST_PAGE = 'first';
    const CSS_LAST_PAGE = 'last';
    const CSS_PREVIOUS_PAGE = 'previous';
    const CSS_NEXT_PAGE = 'next';
    const CSS_INTERNAL_PAGE = 'page';
    const CSS_HIDDEN_PAGE = 'disabled';
    const CSS_SELECTED_PAGE = 'selected';

    /**
     * @var string the CSS class for the first page button. Defaults to 'first'.
     * @since 1.1.11
     */
    public $firstPageCssClass = self::CSS_FIRST_PAGE;

    /**
     * @var string the CSS class for the last page button. Defaults to 'last'.
     * @since 1.1.11
     */
    public $lastPageCssClass = self::CSS_LAST_PAGE;

    /**
     * @var string the CSS class for the previous page button. Defaults to 'previous'.
     * @since 1.1.11
     */
    public $previousPageCssClass = self::CSS_PREVIOUS_PAGE;

    /**
     * @var string the CSS class for the next page button. Defaults to 'next'.
     * @since 1.1.11
     */
    public $nextPageCssClass = self::CSS_NEXT_PAGE;

    /**
     * @var string the CSS class for the internal page buttons. Defaults to 'page'.
     * @since 1.1.11
     */
    public $internalPageCssClass = self::CSS_INTERNAL_PAGE;

    /**
     * @var string the CSS class for the hidden page buttons. Defaults to 'hidden'.
     * @since 1.1.11
     */
    public $hiddenPageCssClass = self::CSS_HIDDEN_PAGE;

    /**
     * @var string the CSS class for the selected page buttons. Defaults to 'selected'.
     * @since 1.1.11
     */
    public $selectedPageCssClass = self::CSS_SELECTED_PAGE;

    /**
     * @var integer maximum number of page buttons that can be displayed. Defaults to 10.
     */
    public $maxButtonCount = 10;

    /**
     * @var string the text label for the next page button. Defaults to 'Next &gt;'.
     */
    public $nextPageLabel;

    /**
     * @var string the text label for the previous page button. Defaults to '&lt; Previous'.
     */
    public $prevPageLabel;

    /**
     * @var string the text label for the first page button. Defaults to '&lt;&lt; First'.
     */
    public $firstPageLabel;

    /**
     * @var string the text label for the last page button. Defaults to 'Last &gt;&gt;'.
     */
    public $lastPageLabel;

    /**
     * @var string the text shown before page buttons. Defaults to 'Go to page: '.
     */
    public $header;

    /**
     * @var string the text shown after page buttons.
     */
    public $footer = '';

    /**
     * @var mixed the CSS file used for the widget. Defaults to null, meaning
     * using the default CSS file included together with the widget.
     * If false, no CSS file will be used. Otherwise, the specified CSS file
     * will be included when using this widget.
     */
    public $cssFile;

    /**
     * @var array HTML attributes for the pager container tag.
     */
    public $htmlOptions = array( );

    /**
     * Initializes the pager by setting some default property values.
     */
    public function init()
    {
        if ( $this->nextPageLabel === null )
            $this->nextPageLabel = Yii::t( 'yii' , 'Next &gt;' );
        if ( $this->prevPageLabel === null )
            $this->prevPageLabel = Yii::t( 'yii' , '&lt; Previous' );
        if ( $this->firstPageLabel === null )
            $this->firstPageLabel = Yii::t( 'yii' , '&lt;&lt; First' );
        if ( $this->lastPageLabel === null )
            $this->lastPageLabel = Yii::t( 'yii' , 'Last &gt;&gt;' );
        if ( $this->header === null )
            $this->header = Yii::t( 'yii' , 'Go to page: ' );

        if ( !isset( $this->htmlOptions['id'] ) )
            $this->htmlOptions['id'] = $this->getId();
        if ( !isset( $this->htmlOptions['class'] ) )
            $this->htmlOptions['class'] = 'yiiPager';
    }

    /**
     * Executes the widget.
     * This overrides the parent implementation by displaying the generated page buttons.
     */
    public function run()
    {
        $this->registerClientScript();
        $buttons = $this->createPageButtons();
        if ( empty( $buttons ) )
            return;
        echo $this->header;
        echo implode( "\n" , $buttons );
        echo $this->footer;
    }

    /**
     * Creates the page buttons.
     * @return array a list of page buttons (in HTML code).
     */
    protected function createPageButtons()
    {
        if ( ($pageCount = $this->getPageCount()) <= 1 )
            return array( );

        list($beginPage , $endPage) = $this->getPageRange();
        $currentPage = $this->getCurrentPage( false ); // currentPage is calculated in getPageRange()
        $buttons = array( );

        // first page
        $buttons[] = $this->createPageButton( $this->firstPageLabel , 0 , $this->firstPageCssClass , $currentPage <= 0 , false );

        // prev page
        if ( ($page = $currentPage - 1) < 0 )
            $page = 0;
        $buttons[] = $this->createPageButton( $this->prevPageLabel , $page , $this->previousPageCssClass , $currentPage <= 0 , false );

        // internal pages
        for ( $i = $beginPage; $i <= $endPage; ++$i )
            $buttons[] = $this->createPageButton( $i + 1 , $i , $this->internalPageCssClass , false , $i == $currentPage );

        // next page
        if ( ($page = $currentPage + 1) >= $pageCount - 1 )
            $page = $pageCount - 1;
        $buttons[] = $this->createPageButton( $this->nextPageLabel , $page , $this->nextPageCssClass , $currentPage >= $pageCount - 1 , false );

        // last page
        $buttons[] = $this->createPageButton( $this->lastPageLabel , $pageCount - 1 , $this->lastPageCssClass , $currentPage >= $pageCount - 1 , false );

        return $buttons;
    }

    /**
     * Creates a page button.
     * You may override this method to customize the page buttons.
     * @param string $label the text label for the button
     * @param integer $page the page number
     * @param string $class the CSS class for the page button.
     * @param boolean $hidden whether this page button is visible
     * @param boolean $selected whether this page button is selected
     * @return string the generated button
     */
    protected function createPageButton( $label , $page , $class , $hidden , $selected )
    {
        $html = '';
        if ( $hidden || $selected )
        {
            $class = ($hidden ? $this->hiddenPageCssClass : $this->selectedPageCssClass);
            $html .= CHtml::link( $label , 'javascript:;' , array( 'class' => $class ) );
        }
        else
        {
            $html .= CHtml::link( $label , $this->createPageUrl( $page ) );
        }
        return $html;
    }

    /**
     * @return array the begin and end pages that need to be displayed.
     */
    protected function getPageRange()
    {
        $currentPage = $this->getCurrentPage();
        $pageCount = $this->getPageCount();

        $beginPage = max( 0 , $currentPage - (int) ($this->maxButtonCount / 2) );
        if ( ($endPage = $beginPage + $this->maxButtonCount - 1) >= $pageCount )
        {
            $endPage = $pageCount - 1;
            $beginPage = max( 0 , $endPage - $this->maxButtonCount + 1 );
        }
        return array( $beginPage , $endPage );
    }

    /**
     * Registers the needed client scripts (mainly CSS file).
     */
    public function registerClientScript()
    {
        if ( $this->cssFile !== false )
            self::registerCssFile( $this->cssFile );
    }

    /**
     * Registers the needed CSS file.
     * @param string $url the CSS URL. If null, a default CSS URL will be used.
     */
    public static function registerCssFile( $url = null )
    {
        if ( $url === null )
            $url = CHtml::asset( Yii::getPathOfAlias( 'system.web.widgets.pagers.pager' ) . '.css' );
        Yii::app()->getClientScript()->registerCssFile( $url );
    }

}
